According to the Washington Post’s tracker of mass public shootings over the past 50 years (defined as a shooting where at least three were killed), there were 948 such culprits, and they came from nearly every imaginable race, religion and socioeconomic background. Additionally, 145 were children or teenagers.
And while the NRA boasts over five million members today, and has been around for the entirety of modern American history, not a single mass public shooter has been a known member.
Please note that every mass shooter has been a Democrat or other leftist ideologue.
Source: Zero Mass Shootings Have Been Committed by Known NRA Members – The Political Insider